We’re getting stressed out because of the electricity bill coming in like rain, but my roommate seems to not care at all. In the evening, he goes and turns on all the lights in every room to the max. When I say, ‘We need to save, it can’t be like this,’ he just says, ‘Come on, don’t exaggerate.’ If I were living with my family, it would be a ‘dad nagging’ situation, but here I don’t even know how to approach it. Do you think this is going to turn into a bigger fight? Is it possible for me to talk to him and find a solution?
If I had a daughter, I would sit her down and talk to her. I would say, ‘Look, when you pay the bill, you might struggle; it’s not a problem for me, but let’s think about your budget.’ Sometimes people aren’t aware, but they understand when you explain it properly.
Dude, I had a roommate in my dorm who would even leave the nightlight on while sleeping. He only stopped when I said, “I’m paying the bills.” Just be straightforward, don’t stress yourself out for nothing. 
It’s actually like a difference in perspective on life. Sharing the electricity bill doesn’t just mean splitting the money, but also sharing the responsibility. Your suggestion for saving is quite reasonable; maybe setting up a common schedule or rule could work for you.
So, here’s the thing: last night all the lights were on again, and I started trying to sleep in the dark. When I said that, he asked, ‘Why are you worrying so much, aren’t you getting bored?’ Anyway, I guess I’m not calm 
Look, my friend, I understand that you’re overwhelmed by the bills, but is it all about the lights? Maybe it makes more sense to save on other things. If not, just turn off the light at that moment; is there really a need to make it bigger? 
I didn’t understand what you wrote. He says “the electricity has bent our backs,” and then he laughs saying “I won’t give up on the lights.” Where’s the logic in this guy? It’s not a matter of arguing with him, is turning on the lights fun?